Propulsion mechanism for endoscopic systems

ABSTRACT

A self propelled, endoscopic apparatus formed of a flexible, fluid-filled toroid and a motorized or powerable frame. The apparatus may be used to advance a variety of accessory devices into generally tubular spaces and environments for medical and non-medical applications. The apparatus when inserted into a tubular space or environment, such as the colon of a patient undergoing a colonoscopy, is advanced by the motion of the toroid. The toroid&#39;s surface circulates around itself in a continuous motion from inside its central cavity along its central axis to the outside where its surface travels in the opposite direction until it again rotates into its central cavity. As the device advances within the varying sizes, shapes and contours of body lumens, the toroid compresses and expands to accommodate and navigate the environment. The motion of the toroid can be powered or unpowered and the direction and speed may be controlled. The apparatus may be used to transport a variety of accessory devices to desired locations within tubular spaces and environments where medical and non-medical procedures may be performed.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication, Ser. No. 60/462,787, filed Apr. 14, 2003. The entiredisclosure of the above-mentioned application is hereby incorporated byreference.

FIELD OF THE INVENTION

This invention relates to an apparatus useful in medical and non-medicalapplications to introduce accessory devices into collapsible andnon-collapsible, body cavities or canals, pipes, lumens and othergenerally tubular spaces or environments. More particularly, theinvention relates to a propulsion system for endoscopic systems.

BACKGROUND OF THE INVENTION

An endoscope is any instrument used to obtain a view of the interior ofa patient's body using a variety of means to capture and transmit theview to an observer. Endoscopes can also be used to perform a variety ofdiagnostic and interventional procedures such as biopsies and othersmall surgical procedures. Examples of endoscopes include: a colonoscopeused within the colon, a gastroscope used inside the stomach, and abronchoscope used within the trachea and bronchi. Endoscopes are ofteninserted into body cavities or lumens via natural orifices but can alsobe inserted into incisions to gain access to areas of the body where nonatural entrance exists.

Traditional endoscopes consist of a rigid or flexible rod or shaft witha means of collecting and transmitting an image from inside thepatient's body. The rod or shaft is inserted and pushed to the locationof interest. The rod or shaft typically surrounds a number of pathwaysused to house fiber optic cables and route instruments, catheters,devices, gasses, liquids and other substances in and out of the area ofinterest.

Traditional endoscopes require a minimal rigidity for successfulinsertion and work well when the body cavity or canal, or other lumenshaving curves and turns. However, when it is constricted, convoluted andconsists of many curves, as is the case with the colon, it can bedifficult or impossible to push the endoscope to its desired location.Steerable articulating endoscopes are often used to make navigation ofturns easier; however, the increased friction associated with eachadditional turn limits the number of turns that can be navigatedsuccessfully and ultimately limits the distance an endoscope can beintroduced into the patient's body. In addition, the increased forcerequired to complete more turns and corners raises the risk ofcomplications such as bowel perforation as well as the discomfort andpain experienced by the patient. It would be useful to have an apparatusfor endoscopic medical procedures that can navigate in such environmentsand can overcome the physical and procedural limitation of traditionalendoscopes. It would further be useful if such an apparatus wereself-propelled.

Endoscopic devices may also be utilized in non-medical or commercial andindustrial applications to obtain views from or introduce instruments ordevices into generally tubular spaces or environments such as lumens,sections of pipe or other structures, which may have a number of curvesand turns. Such tubular spaces or environments may be partially occludedor have buildup on their interior surfaces and thus present a irregularinternal shape or diameter. To navigate through such spaces andenvironments, it would be useful to have a device or apparatus that canadapt to the internal shape or diameter of the space or environment intowhich it is introduced and of further use if the apparatus wereself-propelled.

SUMMARY OF THE INVENTION

The invention in it various embodiments is a propulsion apparatus thatcan be used to transport accessory devices within body cavities orcanals, sections of pipe, lumens, and other generally tubular spaces andenvironments and is generally comprised of a toroid and a powered ormotorized frame. The motion of the toroid can be powered or unpoweredand the direction and speed may be controlled.

In an embodiment of the invention, the apparatus is comprised of atoroid and a frame. The toroid is a fluid-filled, enclosed ring formedof a flexible material. The enclosed ring defines a central cavity,having an interior volume and presenting an exterior surface and aninterior surface which move continuously in opposite directions when theapparatus is in motion.

In one embodiment, the frame is formed of a support structure, a housingstructure and a series of at least two sets of interlocking rollers orskids located on the support and housing structures. The supportstructure is located within the interior volume of the enclosed ring.The housing structure is concentrically and coaxially located relativeto the support structure and disposed in the central cavity of theenclosed ring. The rollers or skids are located so as to maintain thetwo structures in a fixed spatial relationship with the flexiblematerial of the enclosed ring being positioned between the twostructures and the rollers or skids located thereon.

In another embodiment, the frame is formed of a support structurelocated within the interior volume of the enclosed ring and a series ofat least two sets of interlocking rollers or skids located on thesupport structure. The rollers or skids are located so as to maintainthe flexible material of the enclosed ring between them.

In other embodiments of the invention, the apparatus is a propulsionapparatus for transport of accessory devices. The apparatus is comprisedof a toroid and a powered frame. The toroid is a fluid-filled, enclosedring formed of a flexible material. The enclosed ring defines a centralcavity and has an interior volume. The powered frame is formed of asupport structure and housing structure or a support structure alone. Aseries of at least two sets of interlocking rollers or skids located onthe support and housing structures or on the support structure in thecase there is no housing structure. The support structure is locatedwithin the interior volume of the enclosed ring. The housing structureis concentrically and coaxially located relative to the supportstructure and disposed within the central cavity of the enclosed ring.The rollers or skids are located so as to maintain the two structures ina fixed spatial relationship with the flexible material of the enclosedring being positioned between the two structures and the rollers orskids located thereon. The rollers may be connected to a power sourceand when powered provides a motive, directional force to the flexiblematerial.

In its various embodiments, the apparatus of the invention may furthercomprise at least one accessory device. Depending upon whether theapparatus is to be used for medical or non-medical applications, the atleast one accessory device may be selected from the group consisting ofendoscopes, cameras, video processing circuitry, fiber optic cables,electronic communication cables, lasers, surgical instruments, medicalinstruments, diagnostic instruments, instrumentation, sensors, stentcatheters, fluid delivery devices, drug delivery devices, electronicdevices, tools, sampling devices, assay devices, articulating segments,cables to articulate the articulating segments, other accessory devices,and combinations thereof.

The apparatus of the invention may further comprise a power sourceconnected to the rollers which when powered provide a motive force tothe flexible material of the enclosed ring. The power source may be anexternal power source or an internal power source and may be transmittedthrough the shaft by various means.

In its various embodiments, the apparatus of the invention may furthercomprise an accessory tube. The accessory tube has at least one pathwaythrough which accessory devices can be inserted into the patient orconnected to external supporting devices.

The apparatus of the invention may be utilized to perform medical ornon-medical procedures. In an embodiment of a procedure according to theinvention, the apparatus is utilized for medical procedures. Theprocedure of this embodiment comprising the steps of: introducing aself-propellable, endoscopic apparatus according to the invention intothe rectum and anal canal of a patient, the apparatus being equippedwith at least one accessory device and connected to at least oneexternal support device; powering the apparatus to propel the apparatusforward through the anal canal and into the colon up to a location inthe colon at which at least one medical procedure is to be performed;performing the at least one medical procedure with the at least oneaccessory device; optionally, serially propelling the apparatus toanother location in the colon at which the at least one medicalprocedure is to be performed and performing said at least one medicalprocedure; propelling the apparatus backward through the colon and intothe anal canal; and removing the apparatus from the patient.

In another embodiment of the invention, an endoscopic procedure isprovided. The endoscopic procedure comprises the steps of: introducing aself-propellable, endoscopic apparatus into the generally tubular spaceor environment, the apparatus being equipped with at least one accessorydevice and connected to at least one external support device; poweringthe apparatus to propel and navigate the apparatus forward in thetubular space to a location at which at least one endoscopic procedureis to be performed; performing the at least one endoscopic procedurewith the at least one accessory device; optionally, serially propellingthe apparatus to another location in the tubular space at which the atleast one endoscopic procedure is to be performed and performing said atleast one endoscopic procedure; propelling the apparatus backwardthrough tubular space; and removing the apparatus from the tubularspace.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an apparatus in accordance with anexemplary embodiment of the invention.

FIG. 2 is a sectional view of an apparatus in accordance with anadditional exemplary embodiment of the invention.

FIG. 3 is an axial cross-sectional view of an apparatus in accordancewith an exemplary embodiment of the present invention.

FIG. 4 is an axial cross-sectional view of an apparatus in accordancewith an additional exemplary embodiment of the present invention.

FIG. 5 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention.

FIG. 6 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention.

FIG. 7 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an additional exemplary embodiment of the invention.

FIG. 8 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention.

FIG. 9 is an enlarged, partial cross-sectional view of an apparatus inaccordance with an additional exemplary embodiment of the invention.

FIG. 10 is an additional enlarged, partial cross-sectional view of theapparatus shown in the previous figure.

FIG. 11 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention.

FIG. 12 is an additional enlarged, partial cross-sectional view of theapparatus shown in the previous figure.

FIG. 13 is an enlarged, partial cross-sectional view of an apparatus inaccordance with an additional exemplary embodiment of the presentinvention.

FIG. 14 is a cross-sectional view of a bladder in accordance with anexemplary embodiment of the present invention.

FIG. 15 is an additional cross-sectional view of bladder shown in theprevious figure.

DETAILED DESCRIPTION OF THE INVENTION

The self-propellable or self-propelled endoscopic system or apparatus ofthe invention can be utilized to transport a variety of accessorydevices to desired locations within a number of generally tubular spacesand environments, both collapsible and non-collapsible, for medical,industrial and commercial applications. With the system of theinvention, an operator, such as a doctor, medical or other technician,can navigate and traverse within generally tubular spaces and/orenvironments whether of standard or non-standard dimensions and/or ofuniform or non-uniform quality that cause difficulty when navigated bypushing a rod or “snake” through it. Examples of such spaces orenvironments would include, but are not limited to a circular, square,rectangular, or other shaped tube or a tube presenting one or more suchshapes along its length that is partially occluded or interior surfaceof which is irregular, possibly due to material buildup on the surface.And may further include a route with varying diameters, constrictionsand curves.

FIG. 1 is a sectional view of an apparatus 100 in accordance with anexemplary embodiment of the invention. With reference to FIG. 1 it willbe appreciated that the system or apparatus 100 of the invention employsa toroid 102. In the embodiment of FIG. 1, the toroid 102 comprises abladder 104 of a flexible material 106. The flexible material 106 ofbladder 104 has an interior surface 120 and an exterior surface 122.Interior surface 120 of flexible material 106 defines an interior volume124 of bladder 104. In some embodiments of the present invention,interior volume 124 of bladder 104 contains or is filled with a fluid, agas, liquid or combination thereof. Exterior surface 122 of flexiblematerial 106 defines a central cavity 126.

The apparatus 100 shown in FIG. 1 also includes a frame 108. Frame 108both supports and interacts with flexible material 106 of bladder 104.Frame 108 is formed of a support structure 128 and a housing structure130. With reference to FIG. 1, it will be appreciated that housingstructure 130 is disposed in central cavity 126 defined by exteriorsurface 122 of flexible material 106 of bladder 104. Also with referenceto FIG. 1, it will be appreciated that support structure 128 is disposedwithin interior volume 124 defined by interior surface 120 of flexiblematerial 106 of bladder 104.

Support structure 128 and housing structure 130 each rotatably support aplurality of rollers. In FIG. 1, a pair of motive rollers 134 are showncontacting flexible material 106 of bladder 104. In the embodiment ofFIG. 1, rotation of motive rollers 134 will cause flexible material 106to move relative to the rotational axis of each motive roller 134. Inthe embodiment of FIG. 1, each motive roller 134 comprises a pluralityof teeth 140. With reference to FIG. 1, it will be appreciated that theteeth 140 of each motive roller 134 mate with a first thread 142 of aworm gear 144. Accordingly, in the embodiment of FIG. 1, rotation ofworm gear 144 will cause motive rollers 134 to rotate.

The power for rotating motive rollers 134 can be any of a variety ofinternal or external power sources known to those skilled in the art tobe suitable for the given application. In the case of electrical power,the power source may be stored inside the apparatus, or the power may betransmitted via wires from outside the patient or space through anaccessory tube (not shown) connected to the apparatus or to one or moreelectrical motors located inside the housing structure or otherwiseoperatively connected to motive rollers 134 and/or worm gear 144. Theelectrical motors, in turn, power the motive rollers 134 and/or wormgear 144. In the case of mechanical power, rollers 134 and/or worm gear144 may be powered by a thin, flexible, spinning rod or wire poweredfrom a remote motor located outside the patient or space. The motion ofthe rod or wire is transmitted to the rollers located on the housingstructure. Mechanical power may also be transmitted by a spinning spiralor spring component located inside or outside of the apparatus. Thispower may be manually generated.

In the embodiment of FIG. 1, housing structure 130 rotatably supports aplurality of stabilizing rollers 136. With reference to FIG. 1, it willbe appreciated that each stabilizing roller 136 contacts exteriorsurface 122 of flexible material 106 of bladder 104. In the embodimentof FIG. 1, a suspended stabilizing roller 138 is located proximate eachstabilizing roller 136. Each suspended stabilizing roller 138 contactsinterior surface 120 of flexible material 106 of bladder 104. In theembodiment of FIG. 1, each suspended stabilizing roller 138 defines agroove 146 that is dimensioned to receive a portion of flexible material106 and a portion of a stabilizing roller 136.

In the embodiment of FIG. 1, each suspended stabilizing roller 138 ispivotally coupled to an arm 148. In some useful embodiments of thepresent invention, each arm 148 and suspended stabilizing roller 138 actto bias exterior surface 122 of flexible material 106 against astabilizing roller 136. Also in FIG. 1, a plurality of suspended motiverollers 132 are disposed proximate each motive roller 134. Eachsuspended motive roller 132 is pivotally supported by support structure128. In some useful embodiments of the present invention, supportstructure 128 and suspended motive rollers 132 act to bias exteriorsurface 122 of flexible material 106 against motive rollers 134.

For some applications, bladder 104 may be generally longer than it iswide. However, for other applications or depending upon the size ordimension of the space or environment into which the toroid 102 is to beintroduced, the bladder 104 may be of substantially equal length andwidth or may be wider than it is long.

FIG. 2 is a sectional view of an apparatus 200 in accordance with anadditional exemplary embodiment of the invention. With reference to FIG.2 it will be appreciated that apparatus 200 comprises a bladder 204 thatis generally toroidal or ring shaped. Bladder 204 comprises a flexiblematerial 206. Flexible material 206 of bladder 204 has an interiorsurface 220 and an exterior surface 222. Interior surface 220 offlexible material 206 defines an interior volume 224 of bladder 204. Insome embodiments of the present invention, interior volume 224 ofbladder 204 contains or is filled with a fluid, a gas, liquid orcombination thereof. Exterior surface 222 of flexible material 206defines a central cavity 226.

The apparatus 200 shown in FIG. 2 also includes a frame 208. Frame 208both supports and interacts with the flexible material 206 of thebladder 204. Frame 208 comprises a support structure 228 and a housingstructure 230. With reference to FIG. 2, it will be appreciated thathousing structure 230 is disposed in central cavity 226 defined byexterior surface 222 of flexible material 206 of bladder 204. Also withreference to FIG. 2, it will be appreciated that support structure 228is disposed within interior volume 224 defined by interior surface 220of flexible material 206 of bladder 204.

Support structure 228 and housing structure 230 each rotatably support aplurality of rollers. In FIG. 2, a plurality motive rollers 234 areshown contacting flexible material 206 of bladder 204. In the embodimentof FIG. 2, rotation of motive rollers 234 is capable of causing flexiblematerial 206 to move relative to the rotational axis of each motiveroller 234. In the embodiment of FIG. 2, each motive roller 234comprises a plurality of teeth 240. Each motive roller 234 is capable ofmating with a worm gear 244.

With reference to FIG. 2, it will be appreciated that worm gear 244comprises a first thread 242 and a second thread 243. In FIG. 2, theteeth 240 of a first set of motive roller 234 are shown mating withfirst thread 242 of worm gear 244. Accordingly, in the embodiment ofFIG. 2, rotation of worm gear 244 will cause the first set of motiverollers 234 to rotate.

In some embodiments of an apparatus in accordance with an exemplaryembodiment of the present invention, a one or more motive rollers arepowered by a worm gear. A housing structure of the apparatus may containa hollow cavity to hold the worm gear in place as illustrated, forexample, in FIG. 2. This hollow cavity allows the worm gear 244 torotate relative to housing structure 230. Worm gear 244 may also moveforwards and backward along the central axis of the apparatus in theembodiment of FIG. 2. This movement allows second thread 243 of wormgear 244 to selectively engage a second set of motive rollers whilefirst thread 242 disengages from first set of motive rollers 234. Thisselective engagement may facilitate forwards and backwards movement ofthe apparatus. In a variation of this embodiment, the apparatus may beconfigured so that the first and the second set of motive rollers 234respectively engage first and second threads 242, 243.

In the embodiment of FIG. 2, housing structure 230 rotatably supports aplurality of stabilizing rollers 236. With reference to FIG. 2, it willbe appreciated that each stabilizing roller 236 contacts the exteriorsurface 222 of flexible material 206 of bladder 204. In the embodimentof FIG. 2, a plurality of suspended stabilizing rollers 238 are locatedproximate each stabilizing roller 236. Each suspended stabilizing roller238 contacts interior surface 220 of flexible material 206 of bladder204. In some useful embodiments of the present invention, each suspendedstabilizing roller 238 acts to bias exterior surface 222 of flexiblematerial 206 against a stabilizing roller 236.

With continuing reference to FIG. 2, a suspended motive roller 232 isdisposed proximate each motive roller 234. Each suspended motive roller232 is pivotally supported by support structure 228. In some usefulembodiments of the present invention, support structure 228 andsuspended motive rollers 232 act to bias exterior surface 222 offlexible material 206 against motive rollers 234.

Various embodiments of housing structure 230 and support structure 228are possible without deviating from the spirit and scope of the presentinvention. One exemplary embodiment may be viewed as two tubespositioned with one inside the other. The outer tube being the supportstructure which is located within the interior volume of the enclosedring or bladder. The inner tube being the housing structure which islocated within the central cavity. In another embodiment exemplaryembodiment, either the support structure, the housing structure or bothmay be comprised of a series of one or more beams that may or may notform the general shape of a cylinder.

The housing and support structures may be, for example, cylindrical witha circular cross section or they may have a cross section in the shapeof a square, rectangle, triangle, hexagon or any other shape withstraight or curved surfaces or any combination thereof. The framestructures may also be comprised of multiple cross sectional shapesthroughout its length. The flexible material 206 of the bladder 204surface runs between the two tubes which are spaced in fixedrelationship relative to each other. The distance between the two tubesis sufficient to accommodate the interlocking rollers or skids and toallow the flexible material 206 for bladder 204 to pass between thesupport and housing structures even if the material folds over itself oris bunched up.

FIG. 3 is an axial cross-sectional view of an apparatus 300 inaccordance with an exemplary embodiment of the present invention.Apparatus 300 includes a bladder 304 comprising a flexible material 306.The flexible material 306 of bladder 304 has an interior surface 320 andan exterior surface 322. Interior surface 320 of flexible material 306defines an interior volume 324 of bladder 304. In some embodiments ofthe present invention, interior volume 324 of bladder 304 contains or isfilled with a fluid, a gas, liquid or combination thereof. Exteriorsurface 322 of flexible material 306 defines a central cavity 326.

In the embodiment of FIG. 3, a housing structure 330 is disposed incentral cavity 326 defined by exterior surface 322 of flexible material306 of bladder 304. The housing structure 330 rotatably supports aplurality of motive rollers 334. In FIG. 3, motive rollers 334 are showncontacting exterior surface 322 of flexible material 306. In theembodiment of FIG. 3, each motive roller 334 comprises a plurality ofteeth 340. The teeth 340 of each motive roller 334 mate with a thread342 of a worm gear 344. Thus, in the embodiment of FIG. 3, rotation ofworm gear 344 will cause motive rollers 334 to rotate. Also in theembodiment of FIG. 3, rotation of the motive rollers 334 will causeflexible material 306 to move relative to the rotational axis of eachmotive roller 334.

With continuing reference to FIG. 3, it will be appreciated that asupport structure 328 is disposed within an interior volume 324 definedby the interior surface 320 of flexible material 306. In the embodimentof FIG. 3, support structure 328 rotatably supports a plurality ofsuspended motive rollers 332. In FIG. 3, one suspended motive roller 332is shown disposed proximate each motive roller 334. Also in FIG. 3, eachsuspended motive roller 332 can be seen contacting interior surface 320of flexible material 306 of bladder 304. In some useful embodiments ofthe present invention, support structure 328 and suspended motiverollers 332 act to bias exterior surface 322 of flexible material 306against motive rollers 334.

In the exemplary embodiment of FIG. 3, housing structure 330 and supportstructure 328 each have a generally tubular shape. Thus, housingstructure 330 and support structure 328 may be viewed as two tubespositioned with one inside the other. The outer tube being supportstructure 328 which is located within interior volume 324 defined byinterior surface 320 of bladder 304. The inner tube being housingstructure 330 which is located within central cavity 326 defined byexterior surface 322 of bladder 304.

It will be appreciated that various embodiments of housing structure 330and support structure 328 are possible without deviating from the spiritand scope of the present invention. The housing and support structuresmay be, for example, cylindrical with a circular cross section or theymay have a cross section in the shape of a square, rectangle, triangle,hexagon or any other shape with straight or curved surfaces or anycombination thereof. The frame structures may also be comprised ofmultiple cross sectional shapes throughout their length. The flexiblematerial 306 of the bladder 304 surface runs between the two structureswhich are spaced in fixed relationship relative to each other. Thedistance between the two structures is sufficient to accommodate theinterlocking rollers or skids and to allow the flexible material 306 forbladder 304 to pass between the support and housing structures even ifthe material folds over itself or is bunched up.

FIG. 4 is an axial cross-sectional view of an apparatus 400 inaccordance with an additional exemplary embodiment of the presentinvention. Apparatus 400 comprises a bladder 404 of a flexible material406. In FIG. 4 a support structure 428 is shown disposed within aninterior volume 424 defined by the interior surface 420 of flexiblematerial 406. In the embodiment of FIG. 4, support structure 428rotatably supports a plurality of suspended stabilizing rollers 438.With reference to FIG. 4, it will be appreciated that each suspendedstabilizing roller 438 contacts the interior surface 420 of flexiblematerial 406 of bladder 404. In some useful embodiments of the presentinvention, support structure 428 and suspended stabilizing roller 438act to bias exterior surface 422 of flexible material 406 against astabilizing roller 436.

In the embodiment of FIG. 4, a housing structure 430 is disposed in acentral cavity 426 defined by an exterior surface 422 of flexiblematerial 406 of bladder 404. Housing structure 430 rotatably supports aplurality of stabilizing rollers 436. With reference to FIG. 4, it willbe appreciated that each stabilizing roller 436 contacts the interiorsurface 420 of flexible material 406 of bladder 404. In the embodimentof FIG. 4, each suspended stabilizing roller 438 defines a groove 446that is dimensioned to receive a portion of flexible material 406 and aportion of a stabilizing roller 436.

FIG. 5 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention. Apparatus 500comprises a housing structure 530 and a support structure 528. Housingstructure 530 rotatably supports a motive roller 534 and supportstructure 528 rotatably supports a plurality of suspended motive rollers532. A flexible material 506 is disposed between motive roller 534 andsuspended motive rollers 532. Flexible material 506 may form, forexample, a portion of a bladder in accordance with the presentinvention. Suspended motive rollers 532 are rotatably supported by asupport structure 528. In the embodiment of FIG. 5, housing structure530 rotatably supports a worm gear 544. A first thread 542 of worm gear544 engages teeth 540 of motive roller 534. In the embodiment of FIG. 5,rotation of worm gear 544 will cause motive roller 534 to rotate.Rotation of motive roller 534, in turn, causes flexible material 506 tomove relative to housing structure 530. With reference to FIG. 5, itwill be appreciated that flexible material 506 has an interior surface520 and an exterior surface 522.

FIG. 6 is an enlarged, partial, cross-sectional view of an apparatus 600in accordance with an exemplary embodiment of the invention. Apparatus600 comprises a housing structure 630 that rotatably supports a wormgear 644. A first thread 642 of worm gear 644 engages the teeth 640 of amotive roller 634. Motive roller 634 is rotatably supported by housingstructure 630. A flexible material 606 is disposed between motive roller634 and a skid 650. Flexible material 606 may form, for example, aportion of a bladder in accordance with the present invention.

In the embodiment of FIG. 6, rotation of worm gear 644 causes rotationof motive roller 634. Rotation of motive roller 634, in turn, causesflexible material 606 to move relative to housing structure 630. Withreference to FIG. 6, it will be appreciated that skid 650 contacts aninterior surface 620 of flexible material 606. In some usefulembodiments of the present invention, skid 650 acts to bias an exteriorsurface 622 of flexible material 606 against motive roller 634.

FIG. 7 is an enlarged, partial, cross-sectional view of an apparatus 603in accordance with an additional exemplary embodiment of the invention.Apparatus 603 comprises a housing structure 630 that rotatably supportsa motive roller 634. A flexible material 606 is disposed between motiveroller 634 and a skid 650. In the embodiment of FIG. 7, a pair ofsprings 652 act to bias skid 650 against an interior surface 620 offlexible material 606. Springs 652 are diagrammatically illustrated inFIG. 7. Springs 652 may comprise, for example, sheet metal arms. Acompression motion and an extension motion of springs 652 and skid 650are illustrated with arrows in FIG. 7.

In some useful embodiments of the present invention, skid 650 andsprings 652 act to bias an exterior surface 622 of flexible material 606against motive roller 634. Teeth 640 of motive roller 634 engage a firstthread 642 of a worm gear 644 that is rotatably supported by housingstructure 630. In the embodiment of FIG. 7, rotation of worm gear 644causes rotation of motive roller 634. Rotation of motive roller 634, inturn, causes flexible material 606 to move relative to housing structure630.

FIG. 8 is an enlarged, partial, cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the invention. Apparatus 700includes a frame 708 comprising a housing structure 730 and a supportstructure 728. Housing structure 730 rotatably supports a motive roller734 and support structure 728 rotatably supports a plurality ofsuspended motive rollers 732. A flexible material 706 is disposedbetween motive roller 734 and suspended motive rollers 732.

Suspended motive rollers 732 are rotatably supported by a supportstructure 728. A pair of springs 752 of support structure 728 arediagrammatically illustrated in FIG. 8. In the embodiment of FIG. 8,springs 752 act to bias suspended motive rollers 732 against an interiorsurface 720 of flexible material 706. Springs 752 may comprise, forexample, sheet metal arms. A compression motion and an extension motionof springs 752 and suspended motive rollers 732 are illustrated witharrows in FIG. 8.

In the embodiment of FIG. 8, housing structure 730 rotatably supports aworm gear 744. A first thread 742 of worm gear 744 engages teeth 740 ofmotive roller 734. In the embodiment of FIG. 8, rotation of worm gear744 will cause motive roller 734 to rotate. Rotation of motive roller734, in turn, causes flexible material 706 to move relative to housingstructure 730.

FIG. 9 is an enlarged, partial cross-sectional view of an apparatus 800in accordance with an additional exemplary embodiment of the invention.With reference to FIG. 9 it will be appreciated that apparatus 800comprises a bladder 804. In some embodiments of the present invention,bladder has a generally toroidal or ring shape. Bladder 804 comprises aflexible material 806. Flexible material 806 of bladder 804 has aninterior surface 820 and an exterior surface 822. Interior surface 820of flexible material 806 defines an interior volume 824 of bladder 804.In some embodiments of the present invention, interior volume 824 ofbladder 804 contains or is filled with a fluid, a gas, liquid orcombination thereof. Exterior surface 822 of flexible material 806defines a central cavity 826.

The apparatus 800 shown in FIG. 9 also includes a frame 808. Frame 808both supports and interacts with the flexible material 806 of thebladder 804. Frame 808 comprises a support structure 828 and a housingstructure 830. In the embodiment of FIG. 9, housing structure 830rotatably supports a stabilizing roller 836 and support structurerotatably supports a suspended stabilizing roller 838. With reference toFIG. 9, it will be appreciated that suspended stabilizing roller 838contacts the interior surface 820 of flexible material 806 of bladder804. Stabilizing roller 836 is shown contacting an exterior surface 822of flexible material 806 of bladder 804. The rotation of the rollers andthe movement of flexible material 806 are illustrated with arrows inFIG. 9.

FIG. 10 is an additional enlarged, partial cross-sectional view ofapparatus 800 shown in the previous figure. In some useful embodimentsof the present invention, suspended stabilizing roller 838 acts to biasexterior surface 822 of flexible material 806 against stabilizing roller836. In the embodiment of FIG. 10, an arm 848 of support structure 828acts to bias suspended stabilizing roller 838 against interior surface820 of flexible material 806. A flexing motion of arm 848 is illustratedusing arrows in FIG. 10.

FIG. 11 is an enlarged, partial, cross-sectional view of an apparatus900 in accordance with an exemplary embodiment of the invention.Apparatus 900 comprises a housing structure 930 that rotatably supportsa worm gear 944. A stabilizing roller 936 is rotatably supported byhousing structure 930. A flexible material 906 is disposed betweenstabilizing roller 936 and a skid 950. Flexible material 906 may form,for example, a portion of a bladder in accordance with the presentinvention. With reference to FIG. 11, it will be appreciated that skid950 contacts an interior surface 920 of flexible material 906. In someuseful embodiments of the present invention, skid 950 acts to bias anexterior surface 922 of flexible material 906 against stabilizing roller936.

FIG. 12 is an additional enlarged, partial cross-sectional view ofapparatus 900 shown in the previous figure. Skid 950 of apparatus 900 isshown in cross section in FIG. 12. With reference to FIG. 12, it will beappreciated that skid 950 defines a depression 956. In the embodiment ofFIG. 12, depression 956 is dimensioned to receive a portion of flexiblematerial 906 and a portion of stabilizing roller 936. The rotation ofstabilizing roller 936 and the motion of flexible material 906 areillustrated with arrows in FIG. 12.

FIG. 13 is an enlarged, partial cross-sectional view of apparatus 900 inaccordance with an additional exemplary embodiment of the presentinvention. Apparatus 900 includes a frame 908 comprising a housingstructure 930 and a support structure 928. A stabilizing roller 936 isrotatably supported by housing structure 930. A flexible material 906 isdisposed between stabilizing roller 936 and a skid 950. With referenceto FIG. 13, it will be appreciated that skid 950 contacts an interiorsurface 920 of flexible material 906. In some useful embodiments of thepresent invention, skid 950 acts to bias exterior surface 922 offlexible material 906 against stabilizing roller 936. In the embodimentof FIG. 13, an arm 948 of support structure 928 acts to bias skid 950against interior surface of flexible material 906. A flexing motion ofarm 948 is illustrated using an arrow in FIG. 13.

FIG. 14 is a cross-sectional view of a bladder 104 in accordance with anexemplary embodiment of the present invention. Bladder 104 comprises aflexible material 106. The movement of flexible material 106 isillustrated with arrows in FIG. 14. With reference to FIG. 14, anexterior portion of bladder 104 can be viewed as moving in one directionwhile an interior portion of bladder 104 is moving in the oppositedirection. The result is that the entire shape can move along itscentral axis while the external material rolls around itself. Thus, theflexible material may be described as circulating around and through theframe in a continuous motion from inside the central cavity long iscentral axis to the outside where the exterior surface of the flexiblematerial travels along in contact with the interior surface of agenerally tubular space or environment or other lumen. A traveldirection of bladder 104 is labeled TD in FIG. 14. This motion is welladapted to travel within a generally cylindrical or tubular space, evena collapsible one, such as exists with the colon or rectal canal. Theentire object moves with minimal to no slipping because its exteriorsurface remains in relatively constant or continuous contact with theinterior of the space while the interior surface of the flexiblematerials moves forward in the direction of travel as shown.

FIG. 15 is an additional cross-sectional view of bladder 104 shown inthe previous figure. In the embodiment of FIG. 15, bladder 104 istraveling a in second travel direction TD that is generally opposite thetravel direction shown in the previous figure. The movement of flexiblematerial 106 of bladder 104 is illustrated with arrows in FIG. 15. Withreference to FIG. 15, an exterior portion of bladder 104 can be viewedas moving in one direction while an interior portion of bladder 104 ismoving in the opposite direction.

In some exemplary embodiments of an apparatus in accordance with thepresent invention, a frame is formed of a support structure and a seriesof at least two sets of interlocking rollers or skids located on thesupport structure. The support structure is located within the interiorvolume of the enclosed ring. The rollers or skids are located so as tomaintain the flexible material of the enclosed ring between them. Tofurther accommodate folds and wrinkles in the flexible material therollers or skids may be suspended and may apply force to the flexiblematerial and the matching rollers or skids. Embodiments of possiblesuspension mechanisms are illustrated in the figures.

The ends of support and housing structures may be tapered for someapplications. Embodiments of the invention having tapered ends arewell-suited, but not necessary for medical applications and procedures,e.g., colonoscopy or rectal examination. However, such tapering is notnecessary for all applications, particularly those involving spaces orenvironments of large dimension. The tapered ends of the support andhousing structures may serve a number of functions, including, but notlimited to allowing the two structures to fit and work together withoutsliding apart; presenting a smooth and gradual surface to over which theflexible material travels, and easing the apparatus' throughconstrictions and its passage around curves and corners.

The series of at least two sets of interlocking rollers or skids arelocated on the support and housing structures or in the case where onlya support structure is utilized, the rollers or skids are located on thesupport structure. A set of rollers or skids may be comprised of one ormore roller, one or more skid or combination thereof located on one ormore of the structures. A set may be formed of a single roller or skid,a pair of adjacent rollers or skid, a single roller or skid on onestructure and a pair comprised of two or more rollers, two or more skidsor a combination of both on the other, and other variations andcombinations of rollers and skids located in corresponding alignedposition on each structure. The rollers or skids are interlocked in twodirections, along and across the apparatus' central axis. Theinterlocking is done in such a way as to maintain a generally constantor fixed distance between the support and housing structures, so thatthey are in a generally fixed spatial relationship. As shown in thefigures, the flexible material of the enclosed ring passes between therollers or skids. This helps to prevent the toroid's flexible materialfrom being compressed between the two structures except where itinteracts with the rollers or skids. When powered, the rollers engagethe flexible material and provide a motive, directional force to theflexible material which allows the apparatus to move in a forward orbackward direction. With the exterior surface of the enclosed ringcontacting and conforming to the interior surface or surfaces of agenerally tubular space or environment, the powering of the rollersmoves the flexible material as illustrated in the figures. This movementof the flexible material provides the self-propulsion for the apparatus.

If unpowered, the rollers or skids provide a means of facilitating themotion of the flexible material between the support and housingstructures, for example when the apparatus is initially beingintroduced. When propelled, preferably, only the rollers on theadvancing side of the apparatus are powered. This will tend to keep theflexible material from wrinkling, kinking and bunching-up by pulling theflexible material through the toroid's central cavity instead of pushingit. However, the apparatus can be operated with the rearward roller(rearward relative the direction of motion) being powered or bothforward and rearward rollers being powered.

The fluid-filled toroid is also well adapted to the numerous curves,corners and constrictions found in body cavities and lumens. As one partof the shape is squeezed or pushed the liquid or gas is displaced andaccommodated by the flexibility of the bladder.

The apparatus may include an accessory tube, such as a flexible tube,connected to the apparatus and leading outside the patient or otherspace into which it is introduced. For example, as the apparatus entersand travels within the patient, the tube remains connected and is pulledby the device. It can also be pushed or pulled as a means of moving theinside a patient or other space. The accessory tube can be a singlepathway or conduit or may contain multiple pathways or conduits whichcan be used to insert a variety of accessory devices into the patient orto connect such devices to external support devices know to thoseskilled in the art, including but not limited to computers, analyticalor diagnostic equipment or other electronic equipment appropriate to thegiven application.

Various types of accessory devices can be utilized with or mounted tothe apparatus. Such accessory devices include, but are not limited to,endoscopes, cameras, fiber optic cables, electronic communicationcables, lasers, surgical instruments, medical instruments, diagnosticinstruments, instrumentation, sensors, stent catheters, fluid deliverydevices, drug delivery devices, electronic devices, tools, samplingdevices, assay devices, other accessory devices, and combinationsthereof.

The material requirements for the various components of the inventioncan be fulfilled by a number of substances. For medical applications,all materials must possess a high degree of biocompatibility and becapable of withstanding sterilization methods know to those skilled inthe art, such as radiation, steam or chemical vapor.

The fluid located inside the enclosed ring or bladder may be a liquid,such as a light oil, water, saline solution, lubricant; a gas, such asair, nitrogen, or carbon dioxide; or a combination thereof. Preferably,for medical or veterinary application or use, the fluid will benon-toxic. For the enclosed ring or bladder the flexible material shouldbe a material with puncture, rupture and abrasion resistancecharacteristic as appropriate to the conditions of the interior surfaceof the space or environment into which the apparatus will be introduced.The flexible material may also posses a textured surface that wouldassist its motion against the surface of the lumen it traverses. Othercharacteristics to be considered in the selection of suitable materials,for example, softness, flexibility and conformability. The toroid'smaterial must also be capable of being sealed into an enclosed ring orclosed bladder by some means such as heat sealing, an adhesive or achemical bond. A variety of polymeric or plastic materials can be usedas the flexible material.

The support and housing structures may be formed of either asemi-flexible or semi-rigid material such as a polymer or a rigidmaterial, such as stainless steel, a composite material or combinationsthereof. The rollers or skids will require a material or group ofmaterials that is high in strength and capable of being formed into verysmall parts. The roller material must also provide a sufficiently highdegree of friction (not slip) against the flexible material withoutdamaging it while the skids must provide a sufficiently low degree offriction (slip) against the flexible material without damaging it. Thesurfaces of the support and housing structures may be comprised of oneor more materials that reduce or eliminate friction caused by the motionof the flexible material across the surfaces of the support and housingstructures.

For applications of a non-medical nature, the materials required mustretain most properties described above but do not necessarily requirebiocompatibility or sterilization tolerance. The materials used for theinvention in non-medical applications will require sufficient durabilityand compatibility to suit the environment in which they are to be used.

Though a number of applications and uses of the apparatus of theinvention have been identified herein above, additional applications anduses include, but are not limited to, inspection of difficult to reachpipes, tubes and caverns by carrying a camera or other optical,electrical or mechanical inspection device; transporting remotelycontrolled tools for use in difficult to reach locations; routing orpulling cable, wires rope, etc. through long narrow passages; pushing orpulling material through a pipe by taking advantage of the invention'sability to conform to the shape of its environment allowing it toprovide a seal between the spaces on either side, i.e. the inventioncould facilitate emptying a pipe of material without mixing it with airor other material on the other side of the invention. Many of theseapplications would work equally well if the device was self-propelled orsimply pushed or pulled from the outside.

While exemplary embodiments of this invention and methods of practicingthe same have been illustrated and described, it should be understoodthat various changes, adaptations, and modifications might be madetherein without departing from the spirit of the invention and the scopeof the appended claims.

1. A propulsion apparatus for transport of accessory devices within bodycavities or canals, sections of pipe, lumens, and other generallytubular spaces and environments, comprising: a toroid, the toroid beinga fluid-filled, enclosed ring formed of a flexible material, theenclosed ring defining a central cavity, having an interior volume andpresenting an exterior surface and an interior surface which movecontinuously in opposite directions when the apparatus is in motion; aframe formed of a support structure located within the interior volumeof the enclosed ring, a housing structure concentrically and coaxiallylocated relative to the support structure and disposed in the centralcavity of the enclosed ring; and a series of at least two sets ofinterlocking rollers or skids located on the support and housingstructures, the rollers or skids being located so as to maintain the twostructures in a fixed spatial relationship with the flexible material ofthe enclosed ring being positioned between the two structures and therollers or skids located thereon.
 2. The apparatus of claim 1, furthercomprising at least one accessory device.
 3. The apparatus of claim 1,further comprising a power source connected to the rollers which whenpowered provide a motive force to the flexible material of the enclosedring.
 4. The apparatus of claim 3, wherein the power source is anexternal power source.
 5. The apparatus of claim 3, wherein the powersource is an internal power source.
 6. The apparatus of claim 1, whereinthe flexible material is a polymeric material.
 7. The apparatus of claim1, further comprising a power source for powering the rollers, and atleast one accessory device.
 8. The apparatus of claim 1, furthercomprising an accessory tube, the tube having at least one pathwaythrough which accessory devices can be inserted or connected to externalsupporting devices.
 9. The apparatus of any one of claims 2, 7 or 8,wherein the at least one accessory device is selected from the groupconsisting of endoscopes, cameras, fiber optic cables, electroniccommunication cables, lasers, surgical instruments, medical instruments,diagnostic instruments, instrumentation, sensors, stent catheters, fluiddelivery devices, drug delivery devices, electronic devices, tools,sampling devices, assay devices, other accessory devices, andcombinations thereof.
 10. The apparatus of claim 1, further comprising aworm gear.
 11. The apparatus of claim 1, wherein at least one of therollers is suspended by a spring.
 12. The apparatus of claim 1, whereinat least one of the rollers is rotatably supported by an arm.
 13. Apropulsion apparatus for transport of accessory devices, comprising: atoroid, the toroid being a fluid-filled, enclosed ring formed of aflexible material, the enclosed ring defining a central cavity, havingan interior volume and presenting an exterior surface and an interiorsurface which move continuously in opposite directions when theapparatus is powered; a frame formed of a support structure locatedwithin the interior volume of the enclosed ring, a housing structureconcentrically and coaxially located relative to the support structureand disposed in the central cavity of the enclosed ring; a series of atleast two sets of interlocking rollers or skids located on the supportand housing structures, the rollers or skids being located so as tomaintain the two structures in a fixed spatial relationship with theflexible material of the enclosed ring being positioned between the twostructures and the rollers or skids located thereon; an accessory tube,the tube having at least one pathway through which accessory devices canbe inserted or connected to external supporting devices; at least oneaccessory device inserted through the accessory tube or connectedthrough the accessory tube to at least one external supporting device;and a power source connected to the rollers which when the apparatus ispowered provide a motive, directional force to the flexible material.14. A propulsion apparatus for transport of accessory devices,comprising: a toroid, the toroid being a fluid-filled, enclosed ringformed of a flexible material, the enclosed ring defining a centralcavity and having an interior volume; a powered frame formed of asupport structure located within the interior volume of the enclosedring, a housing structure concentrically and coaxially located relativeto the support structure and disposed within the central cavity of theenclosed ring, a series of at least two sets of interlocking rollers orskids located on the support and housing structures, the rollers orskids being located so as to maintain the two structures in a fixedspatial relationship with the flexible material of the enclosed ringbeing positioned between the two structures and the rollers or skidslocated thereon, the rollers being connected to a power source and whenpowered providing a motive, directional force to the flexible material.15. An endoscopic, medical procedure; comprising the steps of:introducing a self-propellable, endoscopic apparatus into the rectum andanal canal of a patient, the self-propellable endoscopic apparatuscomprising: a toroid, the toroid being a fluid-filled, enclosed ringformed of a flexible material, the enclosed ring defining a centralcavity and having an interior volume; a powered frame formed of asupport structure located within the interior volume of the enclosedring, a housing structure concentrically and coaxially located relativeto the support structure and disposed within the central cavity of theenclosed ring, a series of at least two sets of interlocking rollers orskids located on the support and housing structures, the rollers orskids being located so as to maintain the two structures in a fixedspatial relationship with the flexible material of the enclosed ringbeing positioned between the two structures and the rollers or skidslocated thereon, the rollers being connected to a power source and whenpowered providing a motive, directional force to the flexible material;and at least one accessory device and connected to at least one externalsupport device; powering the apparatus to propel the apparatus forwardthrough the anal canal and into the colon up to a location in the colonat which at least one medical procedure is to be performed; performingthe at least one medical procedure with the at least one accessorydevice; optionally, serially propelling the apparatus to anotherlocation in the colon at which the at least one medical procedure is tobe performed and performing said at least one medical procedure;propelling the apparatus backward through the colon and into the analcanal; and removing the apparatus from the patient.